4300 Range Shift Repair

/ 4300 Range Shift Repair #1  

jpinca

Member
Joined
Jan 18, 2010
Messages
42
Location
South San Francisco Bay, CA
Tractor
JD 2000 4300 HST 4WD
My range shift shaft is broken as is common with this model. This was a rental and the rental yard tried, unsuccessfully, to lock out high range with a strap across the shifter:
IMG_0525.jpg


and then again with a bolt:
IMG_0515.jpg

Neither seems to have worked and when the shaft gave way, it looks like the whole shifter linkage was tossed.

I bought all the parts online from JD Parts and it was pretty easy and the prices weren't too bad. Not good, but better than I feared.
IMG_05281.jpg


Instead of using the stock shaft (which might break again), I bought a piece of chrome plated 5/8" shaft stock from McMaster-Carr along with a couple of different types of shaft seals. I'll cut it to length and drill the two pin holes.
IMG_05291.jpg


Anyway, first course of action was to clean the tractor some so that I could see how it came apart.

IMG_0503.jpg

IMG_0504.jpg


Part of this was from my infamous stuck a few weeks ago, but not all of it by a long shot.

The rockshaft cover was barely visible under all the years of crud.

IMG_0507.jpg

IMG_0501.jpg

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But after a little elbow grease and a water hose, I could see what was what and how all of this might come apart.

IMG_0511.jpg

IMG_0512.jpg



Well, there's the part that caused this exercise
IMG_0514.jpg


The cover came off pretty easy. I ended up removing the SCV first to get better access to the pressure line, but it could probably be done without removing by using the proper wrenches. I don't have flare wrenches this big; I just had some adjustable that were too bulky to fit. Doing it over, I would remove the pressure line from the implement pump. The line hanging over the top of the cover just makes maneuvering the cover a little too awkward. The cover isn't especially heavy, but it isn't balanced and you have to remember that the lift arms rotate freely.
IMG_0516.jpg


There's the shaft we're going to replace
IMG_0518.jpg


Let's drain the oil and make sure the sump isn't full of clutch parts or something else

IMG_0524.jpg

The shift mechanism seems to be painted.

Looking around some more
IMG_0523.jpg

What is that?! It sure looks important.... Turns out it's from the PTO clutch release- one of four fingers. It looks like the pin just fell out as the mounts aren't broken and it looks reusable- good thing as you can't buy just the fingers, you have buy the whole hub. It seems a miracle it didn't pass through some gears. Heck, I must be pretty lucky.

Well, maybe not

IMG_0520.jpg

IMG_0521.jpg


The PTO brake hub is broken and will need to be replaced. It is a $110 part, but it looks like I won't have to split the tractor to replace, just remove the PTO cover and slide it out the back.
This rental was used primarily with the tiller, so the PTO has been used/abused a lot. I'm not sure why the PTO brake isn't rigidly mounted. It can rotate 1/4 turn before it contacts the PTO bearing plate and stops the PTO shaft- hammering the part every time. It seems like this is needlessly hard on parts, especially an aluminum casting.

The range shift will have to wait until next week when I have all the parts to button things up.


<More to come...>
 
Last edited:
/ 4300 Range Shift Repair #2  
It almost hurts me to see how this 4300 was abused. You did get a good deal on it, Right did they pay us to take it? Good luck on getting it back in shape.

DR
 
/ 4300 Range Shift Repair #3  
This rental was used primarily with the tiller, so the PTO has been used/abused a lot. I'm not sure why the PTO brake isn't rigidly mounted. It can rotate 1/4 turn before it contacts the PTO bearing plate and stops the PTO shaft- hammering the part every time. It seems like this is needlessly hard on parts, especially an aluminum casting.

The PTO brake rotates freely a fraction of a full turn, as you found out,
in order to be able to attach the PTO drive shaft easier. Most tractors
I am aware of do not use a PTO brake at all, and that means you can
rotate the PTO shaft manually to get the driveshaft on.

I would consider (on the next 4300 I get) eliminating the PTO brake
entirely. Mine was in better shape, but I found a crack in one plate.

I can't quite make out the parts you found in the sump....are you going
to take photos of them cleaned up?

Anyway, I just got back from the Farm Show and just saw your pix. Good
luck.
 
/ 4300 Range Shift Repair
  • Thread Starter
#4  
I need to finish this post. I misplaced my camera and then....

Here's what the screen looked like. I'm not sure the screen had ever been cleaned although the fluid and HST filter were on a maintenance schedule.
IMG_0531.jpg

P1040233.jpg


Removing the PTO cover gives access to the PTO brake clutch assemble.
P1040231.jpg


Another POV of the loose parts
P1040232.jpg


Broken clutch basket vs new
P1040234.jpg


Here's the new shaft installed and the seal I decided to use. It's just a 5/8" shaft seal from McMaster-Carr too.
IMG_0533.jpg


The new shift linkage installed, but the shaft hasn't been drilled or trimmed. I wanted to be sure I placed the dowel in the correct position for both the shaft seal and the shifter throw. Once I was happy with the position, I carefully drilled through the bellcrank into the shaft from both sides. Not perfect, but the best I could do without a drillpress
IMG_0532.jpg


Linkage adjusted so that the lever stop takes the abuse rather than the shift forks
IMG_0534.jpg


While I had it apart, I cleaned and painted the the back half. It looks better and should be easier to clean.

I've used the heck outta this tractor so far and this repair is working perfectly. I don't recall the exact cost, but subtracting the new fluid, I doubt I have $150 into it.

If there is no stress on the drivetrain, the ranges shift like butter. However it doesn't take much to bind the gears up and make the lever hard to move. I can see how this breakage can happen if you try to force the lever. Using the solid shaft as I did, I expect I've moved the weakest link further inside the tractor.
 
/ 4300 Range Shift Repair #5  
Good work.

Your misplaced camera isn't inside the tranny, right? :)
 
/ 4300 Range Shift Repair #6  
Thanks for the pictures and documentation of the repairs!:thumbsup:
 
/ 4300 Range Shift Repair #7  
I'm following up Egon...great thread and documentation!
 
/ 4300 Range Shift Repair #8  
Roy, I'm particularly interest as I have a 4200 JD. Selecting the range I want can be aggravating at times.:(
 
/ 4300 Range Shift Repair #9  
Roy, I'm particularly interest as I have a 4200 JD. Selecting the range I want can be aggravating at times.:(

I've got a 4400 so I'm interested too. My tractor is a sync-reverser though, not HST.
So far, mine shifts quite smoothly and I want to keep it that way. I bought Fluid Film (based upon several recommendations on TBN...I believe you were one of those recommendations, thank you very much!) to keep these linkages well lubricated.
 
/ 4300 Range Shift Repair #10  
Roy, I changed the hydro fluids so I've got several buckets of nice clear oil that I use. Pour some into a spray type dispenser plastic container from whatever and spray the areas in question.:D
 
/ 4300 Range Shift Repair #11  
Roy, I changed the hydro fluids so I've got several buckets of nice clear oil that I use. Pour some into a spray type dispenser plastic container from whatever and spray the areas in question.:D

And I'm going to guess most linkage problems concerning the range shifter result from lack of lubrication.

I really like my 4400 even though it is massive overkill for my meager little acreage. However, the linkages are much more remote (hence, more potential for breakage and failure) then my previous 670 and 790 tractors (linkages were very short and direct...probably a similar situation with your old Kubota (5100 or 6100?)).
Anyway, after following this thread and others discussing 4300 rebuilds, I'm much more aware of the importance of lubricating these linkages regularly.
 
/ 4300 Range Shift Repair
  • Thread Starter
#12  
While lubricating the linkage is undoubtedly important, I don't think the linkage can be blamed. If the linkage binds, the rod would bend first. I don't see anyone breaking the bellcrank or shifter- those are crazy overkill.

Twisting the shaft means the binding is occurring inside the case. This could be bound up gears, bend forks, heavy detents, or some similar issue.

After doing the repair and using the tractor with lots of shifting, I think 99.99% of breakages are caused by forcing the shifter.

A better design, in my opinion, would have been to size the shaft dowel pin such that it would shear before the stock shaft twists- kinda like a PTO shear bolt. This would move the breakage outside the case and turn a day long repair into an hour repair.
 
/ 4300 Range Shift Repair #13  
Twisting the shaft means the binding is occurring inside the case. This could be bound up gears, bend forks, heavy detents, or some similar issue.

A very strong detent spring is what I found out.

Anyway, I am glad you got it fixed, JP.

I recently got the last JD unit from ATS, and it has already received an
all new clutch/brake, and a new rear axle casting. The whole tractor was
replaced by JD a year after its purchase, so it's a 2001 model. They did
that with at least 3 of their first 2000 model 4300s. The only way to tell
is with the serial # and various date stamps on the tractor. Or the
service records.
 
/ 4300 Range Shift Repair #14  
While lubricating the linkage is undoubtedly important, I don't think the linkage can be blamed. If the linkage binds, the rod would bend first. I don't see anyone breaking the bellcrank or shifter- those are crazy overkill.

Twisting the shaft means the binding is occurring inside the case. This could be bound up gears, bend forks, heavy detents, or some similar issue.

After doing the repair and using the tractor with lots of shifting, I think 99.99% of breakages are caused by forcing the shifter.

A better design, in my opinion, would have been to size the shaft dowel pin such that it would shear before the stock shaft twists- kinda like a PTO shear bolt. This would move the breakage outside the case and turn a day long repair into an hour repair.

The rod, being round stock about .25" diameter, would be "springier" and able to withstand the cyclic movement better. If it broke, it would most like break where it attaches to the member that enters the transmission case. Pretty unlikely...
Forcing the shifter...yep, but that forcing would be reduced by proper lubrication.
I'd also surmise that some operators (especially inexperienced ones such as you'd expect using rental equipment) might not come to a full stop which is required when shifting ranges which puts more stress on the shifter.
I hope the range selector on my 4400 doesn't fail as it appears to be a PITA to repair. At minimum, I expect the life of the unit to be extended by lubricating...that, and proper technique during shifting.
Of course, lubrication isn't going to help much with the strong detent spring Dave (dfkrug) describes in his post just before this one.
 
/ 4300 Range Shift Repair #15  
I hope the range selector on my 4400 doesn't fail
Roy, you should stop by and try the range selector on my tractor. You will never worry about yours ever again. Yours shifts like butter and has clear detents. I wish mine worked 50% as smooth as yours does.
 
/ 4300 Range Shift Repair #16  
At minimum, I expect the life of the unit to be extended by lubricating...that, and proper technique during shifting.
Of course, lubrication isn't going to help much with the strong detent spring Dave (dfkrug) describes in his post just before this one.

I am sure that you will have some idea what pushing too hard is, Roy.
Especially since it is your tractor and you don't want to break it. Just
don't lend it out.

I am more concerned about the force necessary to push my PTO lever....
that one is hard, despite the fix I went through.
 
/ 4300 Range Shift Repair #17  
Roy, you should stop by and try the range selector on my tractor. You will never worry about yours ever again. Yours shifts like butter and has clear detents. I wish mine worked 50% as smooth as yours does.

Yeah, I'd like to do that, Leo...still gotta drop off the Pat's Easy Change part. Has your neighbor installed them yet?
 
/ 4300 Range Shift Repair #18  
I am sure that you will have some idea what pushing too hard is, Roy.
Especially since it is your tractor and you don't want to break it. Just
don't lend it out.

I am more concerned about the force necessary to push my PTO lever....
that one is hard, despite the fix I went through.

Yes, I do have an idea of when it's binding...and I learned years ago to not lend out equipment! If I lend out anything, the operator (me) goes with it.
My rear PTO lever works pretty good (used it on the finishing mower and chipper so far), but I do prefer the direct linkage of the old 790. That 790 was easier to feather the throttle/clutch.

This entire thread, and a couple others discussing 4300 repairs, have been quite enlightening.
 
/ 4300 Range Shift Repair #19  
So this thread had me go out and play with the range shifter some more. I normally keep it in A and have no real need to take it out of A other than to keep everything working smoothly.

I noticed that I can go "past" C which puts it back into neutral. And on the way back to A it stays in N unless I quickly jam it to A and then it'll catch. But if I slowly move to A it will not leave N. So its not adjusted right I guess. Anyone have a picture of what needs adjusted?

Does anyone have an HST with a smooth as butter range selector? And really clear detents? I have to wonder whether the HST vs SyncReverser is the reason for why we all have the same complaint except for Roy.

Yeah, I'd like to do that, Leo...still gotta drop off the Pat's Easy Change part. Has your neighbor installed them yet?
I don't know if he did or not. I'm thinking he won't get to it until he goes to get the snowblower ready. He already did all the ground prep for his mini-farm so I haven't seen him using the tractor recently. I'm gonna be out towards your place later in the week. I was going to figure it out and let you know...
 
/ 4300 Range Shift Repair #20  
So its not adjusted right I guess. Anyone have a picture of what needs adjusted?

Does anyone have an HST with a smooth as butter range selector? And really clear detents?

There is no adjustment really. That assumes parts external to the
gearbox are lubed well and not binding or sloppy. This photo shows the
two collars that are shifted simultaneously by the two forks. If all the
teeth are not lined up right, shifting will not happen. And it is very easy
to go right past the neutral position into the next range.

As for smooth operation, mine is very smooth and easy after my rebuild,
but the detents are not very clearly felt. I may have gone too far in
softening up my detent spring. It was hard to test at the time unless
all the linkages were installed. The shifter gives you so much leverage that
what seems hard enough to turn at the bell crank was way way easier
using the shifter.
 

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